AmericanStandard furnace

[fivebugs]

I have a 2 yr old, 80% gas furnace with a 2-stage blower. I tried to use a back-up generator to run it during a power outage - but I couldn't get it to light. The generator is 3000 watts(4000 surge) I changed the dead circuit from a single pole switch to a short pigtail cord and connect to the generator with an extension cord.

All the cords are good, 12 ga, and the distance was only about 60'. I disconnected all the furnace wires from the house wires and moved them all to the pigtail....The igniter would click, but not light.

I'm told the problem might have been that I didn't connect the grounds effectively. Is that reasonable?

[RBM]

You disconnected "all the furnace wires". How many wires are there?

[tim1198]

I also have an American Standard 2 stage, and just had a power outage last week and was able to hook the furnace to my small generator. Although after taking off the switch and seeing how many pigtails were connected, I connected to the wire coming into the switch and everything was fine. So I'd make absolutely sure that all the pigtails were connected properly.

I'm not an AC guy, but I think there were 2 transformers hooked up to this circuit. I'd guess it's to power the thermostat.. If there are any HVAC pros out there, you can clarify.

I'm sure you already checked, but have to checked to make sure the gas is on? Did the fan run?

Good luck. tim1198

[e-mail] wrote:

[RBM]

That's why I asked the question I did. He should only have to deal with the feed to the furnace, one cable, two wires + ground

[Bob]

The igniter may be sensitive to the polarity of the AC power line relative to ground. Use a plug and receptacle to provide complete isolation between the regular power system and generator. Are the neutral and ground leads from the generator bonded together? This is just one of many issues encountered when trying to tie a portable generator into house wiring.